(1) Field of the Invention
This invention relates to roller mills for grain, and more particularly to a roller mill for rolling cooked feed for cattle.
(2) Description of the Related Art
It is common to feed cattle being fattened for slaughter steamed feed. After the feed is steamed, it is rolled.
When grain is not being fed to the roller mill, the rolls are normally separated or disengaged. When the roller mill is rolling the grain, they are in an engaged position. The engaged position does not necessarily mean that the rolls are contacting one another. Often, they will be separated by 1/64" or less to properly roll the grain. The exact degree of separation depends not only upon the material that is being rolled, but also upon the individual preference of the management.
When the rolls are engaged, they are separated by the prescribed amount by rigid adjustable stops. They are held against the stops by heavy springs. The springs normally hold the rolls against the stops for the minimum clearance, except when a foreign object is in the grain. Regardless of all precautions, often a foreign object such as a piece of metal or other hard object will be in the feed. It is desirable for the rolls to spring open on such an occasion.
Also, it is necessary that the two ends of the rolls or the two bearing blocks holding the rolls be moved forward and back in unison.
The rolls or bearing blocks may be moved only about 1/4" between the engaged and disengaged positions. One roll is stationary and the other is moved between the engaged and disengaged position.
Before my invention, about 90% of the rolls were moved into position by hydraulic cylinders. These hydraulic cylinders operated a tension shaft which moved axially. The axial movement of each tension shaft compressed its spring. The compressed spring exerted about 2,500 pounds of force on the tension shaft.
The distal end of the shaft had a compression spring attached thereto. The distal end and compression spring extended outward from the rolling mill. A housing pad attached to the spring would move the bearing block and thus, the moveable rolls. Since the cylinders operated on hydraulic fluid, it was normally necessary for their operation that the location of the roller mills have available electricity and compressed air for the pressure feed of the hydraulic pumps.